Controllable pitch propeller



April 13, 1943. P. R. LEA

CONTROLLABLE PITCH FROPELLER Filed March 18, 1941 INVENToR. Percy R..Lea

I airplane.

Patented Apr. 13, 1943 UNITED STATES` iPATaNTroFFicE CONTROLLABLE FETCH PELLER Percy R. Lea, Stockton, Calif.

Application March 18, 1941, Serial No. 383,974

12 Claims. Cl. Mii-135.6)

This invention relates to airplane propeller mounting and adjustment; my principal objects being to provide a unit for manually or automatically adjusting the pitch of the propeller blades, which is self-contained, which operates with a negligible lag, and which is faster in operation, simpler and cheaper in construction and requires less upkeep than devices at present in use for this purpose.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specication and claims.

In the drawing similar characters of reference indicate corresponding parts in the several views:

Fig. 1 is a sectional elevation of my improved propeller blade mounting and adjusting unit.

Fig. 2 is a transverse section on the line 2--2 oi' Fig. 1. Fig. 3 is a diagram of an automatic governor device for operating the adjusting unit.

Referring now more particularly to the characters of reference on the drawing, the numeral I denotes a rigid substantially cylindrical housing adapted to be secured in xed connection to one end of the crankcase of the engine of the The engineshaft' or a separate shaft 3 rigidlv connected to said engine shaft, projec into the housing axially thereof.

Fixed on the shaft 3 is a bevel gear 4, facing away from thecran'kcase and meshing with any desired number of bevel pinions B mounted on axial stems 6 disposed in a ilxed position in the housing in radial relation with the gear 4. TheV pinions mesh with another bevel vgear 1, facing 'and the same size as gear 4, and of course axially alined therewith. Thegear 1 is iixed to 'a hollow hub member 8, which is turnably supported in the housing I atits outer'end o'n suitable bearings 49 of an antifriction type. It will therefore be 'seen that as the shaft rotates the hub will rotate also.-

- Turnably mounted in radial bearings Iii formed in the hub are the base lspindles II of the pro-l peller blades I2, and while two diametrally opposed blades are shown, more may be' employed if desired. Fixed on the inner end of thev spindles are bevel gears I3 meshing with a bevel pinion i4 disposed therebetween and axially alined with the gears 4 and 1. The pinion I4 is mounted on a shaft I5 turnably supported in a bearing I6 in the hub and also in the hub in the gear 1, the shaft projecting through said gear in turnable relation thereto. If the propeller is of the tractor typ, the pinion I4 engagesgears I 3 at the rear as shown; and is merely vreversed in position, without other change to the mechanism, if the propeller is of the pusher type. y

Beyond said gear 1, or between the gears 4 and 1, a bevel gear I1 smaller than the gear 1 is xed on the adjacent end of the shaft I5. This gear meshes with one or more bevel pinions I8vwhich in turn mesh with a bevel gear I9 of the same size as gear I1 and fixed rigid or made integral with gear 4.

The pinions I8 are mounted on axial spindles 20 disposed radially of the gears and supported in a ring 2i extending about the pnions, concentric with the shafts and gears. This ring is turnably supported by a surrounding ring 22 which is en gaged and maintained in a fixed position spindles Grof the pinions 5. y

'The ring 22 is therefore held against rotation in the housing, and the ring 2i is normally held rigid with the ring 22 by adjustable means which may be either manually or automatically conl trolled. In the present instance such means is shown as comprising a segmental worm gear 23 rigid with the ring 2 I from which the pinions I8 are supported. This gear is engaged by a worm 24 mounted on a shaft 25 which is journaled and extends transversely of the housing I. A worm Bear 26 is mounted on the shaft 25 which in turn is engaged by a worm 21. This worm is mounted on a rotatable shaft 28 extending lengthwise of the housing, and which may project thence rearwardly as a exible extension past the engine for manual rotation from the pilots seat.

. In operation it will be seenthat with the ring 2| normally held stationary, the gear I1 will'be driven at the same speed as the gear 1 so that the shaft I5 and pinion I4 thereon are stationary relative to the hub 8, and the hub and propeller blades rotate without any rotation of the blade spindles. so that, the blades are maintained in a set position relative to the hub. If,'however, the ring 2| is rotated relative to the ring y22 and the housing I in one direction or the'other, the gear I 1 and consequently the pinion I4 will turn faster or slower than the hub as the case may be as long as said ring 2i is being turned. As a result,A such relative rotation of the pinion I4 causes the. gears I 3 to rotate and thus changes the pitch of the blades, as will be evident.

As soon as the rotation of the ring 2i is halted the pinion I4 again turns at the same speed as the hub, and the propeller blades remain set in their adjusted position until such position is again changed by a further rotation of the ring.

'A suitable governor device is interposed. in the by the assembly, designed along the best known engineering principles and practice, to automatically the other, with any change of speed of the gear il from a predetermined normal.

It will of course be understood that all moyable parts have suitable bearings, the particular type and location of which form no part of this invention. It will also be understood that all parts will be made of the best materials available, and to the highest standards of precision, and that means for proper lubrication will be provided.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfillsthe objects of the invention as set forth herein.

While thisl specication sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as dened by the appended claims.

Having thus described my invention, what l.' claim as new and useful and desire to secure by Letters Patent is:

1. An airplane propeller drive and control u nit comprises a hub, propeller blades turnably mounted in the hub, a fixed housing supporting the hub for rotation, a bevel drive gear in the housing, a driven bevel gear rigid with the hub and concentric with and facing the drive gear, a bevel pinion fixed in the housing and engaging the drive and driven gears, a bevel gear smaller than and fixed to the drive gear between the drive and driven gears, another bevel gear smaller than and turnable relative to the driven gear in facing relation to the rst named bevel gear, a bevel pinion engaging said relatively small bevel gears, connecting means between said other bevel gear and the blades to rotate the latter in opposite directions and relative to the hub when said other gear rotates at a speed different from that of the hub, means mounting said last named bevel pinion for rotation about the axis of the drive gear and means to control the rotation of the mounting means.

2. A unit as in claim 1, in which said connecting means comprises bevel gears fixed on the blades within the hub, a bevel pinion engaging said gears and a shaft connecting the pinion and said other bevel gear and turnably projecting through the driven gear.

3. A unit as in claim 1 in which said mounting means comprises a ring concentric with the drive gear and inside which the last named bevel pinion is mounted and means tum-ably supporting the ring from the housing; the control means being applied to the ring.

4. A unit as in claim l in which said mounting means comprises a ring turnably mounted inthe lil mounted in the hub, a fixed housing supporting the hub for rotation, a bevel drive gear in the housing, a driven bevel gear rigid with the hub and concentric with and facing the drive gear, bevel pinions fixed in the housing in spaced relation about and engaging the drive and driven gears, stub shafts on which said pinions are mounted, a bevel gear smaller than and fixed with the drive gear between the drive and driven gears, another bevel gear smaller than and turnable relative to the driven gear in facing relation to the rst named bevel gear, a bevel pinion engaging said relatively small bevel gears, connecting means between said other bevel gear and the blades to rotate the latter in opposite directions and relative to the hub when said other gear rotates at a speed different from that of the hub, a ring concentric with the drive gear radially in from said bevel pinions and supported in a fixed position by said stub shafts, another ring turnably mounted in and supported by said nrst named ring and inside which said last named bevel pinion is mounted, and means applied to said other ring to control the rotation thereof and including an operating shaft turnably mounted in the housing.

6. A `propeller drive and control unit comprising a hub, propeller blades turnably mounted in the hub, means supporting the hub for rotation, means to rotate the hub including a drive gear concentric with the hub, a bevel gear fixed with the drive gear between the first named gear and the blades and facing the latter, another bevel gear turnable relative to the hub mounted concentric therewith in facing relation to the first named bevel gear, drive connections between said other bevel gear and the blades to rotate the latter in opposite directions and relative to the hub when said other gear rotates at a speed different from that of the hub, a bevel pinion engaging said -bevel gears, means mounting the pinion for rotation in an arcuate path concentric with the axis of the drive gear, and means to control such rotation of the mounting means.

'7. A 'unit as in claim 6, in which the pinion mounting means comprises a ring mounted concentric with and turnable relative to the drive gear; the control means being applied to the ring.

8. A unit as in claim 6, in which the pinion. mounting means comprises a ring mounted concentric with anri turnable relative to the drive gear and the control means comprises a worm gear fixed and concentric with the ring, a worm engaging the worm gear, means turnably mounting the worm in a fixed position relative to the hub and means to rotate the worm.

9. A unit as in claim 6, in which the pinion mounting means comprises a ring mounted concentric with and turnable relative to the drive gear and the control means comprises a gear element fixed and concentric with the ring, another rotary gear element engaging the first named element, means mounting said other element in a fixed position relative to the hub, and means to'rotate said other element.

10. A propeller drive and control unit comprising a. hub, propeller blades turnably mounted in the hub, means supporting the hub for rotation, means to rotate the hub including a drive gear concentric with the hub, a bevel gear fixed with the drive gear between the first named gear and the blades and facing the latter, another bevel gear turnable relative to the hub mounted concentric therewith in f'cing relation to the firstV named bevel gear, drive connections between said` other bevel gear and the blades to rotate the latter in opposite directions and relative to the hub when said other gear rotates at a speed different from that of the hub, a bevel pinion engaging said bevel gears, a stub shaft radial with ,the drive gear on which the Apinion is mounted, a ring radiaily out from the pinion from which the pin projects, means turnably mounting the ring for rotation in a path concentric with the drive gear, and means applied to the ring to control the rotation of the same.

11. A structure as in claim 10, in 'which said ring mounting means comprises another ring surrounding the rst named ring and mounted in a .fixed position, and bearing elements between the rings.

12. In a propeller drive and control lunit, a hub mounted for rotation, propeller blades turn-s ably mounted in the hub. separate and alined drive and driven shafts mounted concentric with the hub, means between the drive shaft and hub to rotate the latter, means connecting the driven shaft and the blades to turn the latter in opposite directions upon rotation of said driven shaft relative to the hub, facing bevel gears on. the adjacent ends of the shafts, a pinion engaging the gears, means mounting the pinion for rotation about the axis of the shafts, and means to control such rotation of the mounting means.

PERCY R. LEA. 

